Several converging lines of evidence point to notable human-nonhuman differences in choices with contrasting short-term and longer-term outcomes. This balancing of immediate against temporally remote consequences is implicit in many issues concerning human health and welfare (e.g., preventive medicine, drug abuse, pollution); it is also a key relationship in cost/benefit interpretations of human and nonhuman behavior, such as optimality theory in behavioral ecology and maximization theory in microeconomics. Thus, understanding the factors responsible for species differences in sensitivity to short-term versus longer-term consequences is of practical as well as theoretical importance. In the proposed research, two related lines of experimentation will be pursued concurrently. One line of work, conducted with pigeons, squirrel monkeys, and humans, seeks to minimize procedural differences, particularly differences in motivational/economic context, of which human-nonhuman discrepancies reported in the literature may be partly a function. A second line of research, conducted with humans only, will focus on relations between verbal and nonverbal functioning, and the participation of such functioning in human- nonhuman differences. In some experiments, the content of instructions provided to subjects will be manipulated to assess the degree to which instruction-following alters sensitivity to programmed consequences. In other experiments, subjects will be trained to assess the degree to which instruction -following alters sensitivity to relations between saying and doing, and to evaluate the feasibility of changing what people say to themselves in ways that alter sensitivity to long-term outcomes. Together, this work will help clarify human- nonhuman differences in choice and self-control, and the degree to which principles discovered in the non-human laboratory are applicable to fairly complex human behavior. In identifying variables of which adaptive choice is a function, this research may also provide a starting point for developing effective self-management techniques in humans.